基于ARM的有源UHF电子标签的应用设计

发布时间：2018-01-13 02:29

本文关键词：基于ARM的有源UHF电子标签的应用设计　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：RFID即射频识别技术,是一种通过无线电对目标进行识别的技术,是物联网发展的基础,目前在国内外发展迅速,已经形成了众多行业规范。其中无源电子标签占据大部分市场份额,而有源电子标签处于发展初期。有源电子标签拥有无源电子标签不具有的传感器功能。通用超高频读写器往往不具有有源电子标签的扩展功能命令。为此本文提出了一种有源UHF电子标签的应用系统设计,包括超高频读写器、天线和有源电子标签。首先读写器射频前端使用分立元件搭建以减少成本。读写器基带信号的处理使用ARM9通过软件实现,其中ARM9的PWM输出用于控制射频开关进行编码,然后对标签返回信号使用中断捕捉并通过软件状态机解码。为适应多任务的上层应用,需将读写程序移植到嵌入式操作系统UCOSII上,并使用VC++编写读写软件,可以通过串口控制读写器的读写。其次,由于天线的好坏直接影响读写器的性能,而市面上的桌面读写器使用的陶瓷天线成本较高,为此本文设计了一款小型UHF PCB天线,该天线采用对称振子结构模型,通过弯折天线臂减小天线尺寸,使用巴伦将天线输入阻抗匹配到50?,使用HFSS13对天线进行建模和仿真优化,最后制作出天线实物。再者,本文使用有源电子标签芯片SL900A,通过HFSS仿真出适合此芯片的PCB天线,进而设计出一款能够记录环境温度的超高频有源电子标签。在上面设计的读写器编解码的基础上,实现该标签的附加功能命令,用于进行无线温度监控。最后对上述设计进行测试。测试内容包括读写器的射频收发电路测试、读写软件测试、天线测试和有源电子标签测试,测试结果表明,系统能正常工作,满足应用要求。
[Abstract]:Radio Frequency Identification (RFID) is a technology for target identification by radio. It is the basis of the development of Internet of things and is developing rapidly at home and abroad. Many industry norms have been formed, in which passive electronic tags account for most of the market share. But the active electronic tag is in the early stage of development. The active electronic tag has the sensor function which the passive electronic tag does not have. The universal UHF reader often does not have the expansion function command of the active electronic tag. An application system of active UHF tag is designed. It includes UHF reader, antenna and active electronic tag. First, the RF front-end of reader is constructed with discrete components to reduce the cost. The reader baseband signal is processed by ARM9 through software. The PWM output of ARM9 is used to control the RF switch to code, then the tag return signal is captured by interrupt and decoded by the software state machine. Need to transplant the read and write program to the embedded operating system UCOSII, and use VC to write read and write software, you can control the reading and writing of the reader through the serial port. Secondly. Because the antenna directly affects the performance of the reader, and the cost of ceramic antenna used in the desktop reader is high, a small UHF PCB antenna is designed in this paper. The antenna adopts a symmetrical dipole structure model, which reduces the antenna size by bending the antenna arm, and uses Barron to match the antenna input impedance to 50? HFSS13 is used to model and simulate the antenna, and finally the antenna object is made. Furthermore, the active tag chip SL900A is used in this paper. The PCB antenna suitable for this chip is simulated by HFSS, and a UHF active electronic tag which can record the ambient temperature is designed. On the basis of the codec of the reader designed above. The additional function command of the tag is used for wireless temperature monitoring. Finally, the above design is tested. The test includes RF transceiver circuit test, read and write software test. The antenna test and active tag test show that the system can work normally and meet the requirements of application.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN820;TP391.44

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